pieceslist.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtGui>

#include "pieceslist.h"

PiecesList::PiecesList(QWidget *parent)
    : QListWidget(parent)
{
    setDragEnabled(true);
    setViewMode(QListView::IconMode);
    setIconSize(QSize(60, 60));
    setSpacing(10);
    setAcceptDrops(true);
    setDropIndicatorShown(true);
}

void PiecesList::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
        event->accept();
    else
        event->ignore();
}

void PiecesList::dragMoveEvent(QDragMoveEvent *event)
{
    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
        event->setDropAction(Qt::MoveAction);
        event->accept();
    } else
        event->ignore();
}

void PiecesList::dropEvent(QDropEvent *event)
{
    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
        QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
        QPixmap pixmap;
        QPoint location;
        dataStream >> pixmap >> location;

        addPiece(pixmap, location);

        event->setDropAction(Qt::MoveAction);
        event->accept();
    } else
        event->ignore();
}

void PiecesList::addPiece(QPixmap pixmap, QPoint location)
{
    QListWidgetItem *pieceItem = new QListWidgetItem(this);
    pieceItem->setIcon(QIcon(pixmap));
    pieceItem->setData(Qt::UserRole, QVariant(pixmap));
    pieceItem->setData(Qt::UserRole+1, location);
    pieceItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable
                        | Qt::ItemIsDragEnabled);
}

void PiecesList::startDrag(Qt::DropActions supportedActions)
{
    QListWidgetItem *item = currentItem();

    QByteArray itemData;
    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
    QPixmap pixmap = qVariantValue<QPixmap>(item->data(Qt::UserRole));
    QPoint location = item->data(Qt::UserRole+1).toPoint();

    dataStream << pixmap << location;

    QMimeData *mimeData = new QMimeData;
    mimeData->setData("image/x-puzzle-piece", itemData);

    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2));
    drag->setPixmap(pixmap);

    if (drag->start(Qt::MoveAction) == Qt::MoveAction)
        delete takeItem(row(item));
}